The present invention relates to a new and distinct cultivar of Begonia, of the family Begoniaceae, and given the cultivar name, ‘TNBEGSS’. The new cultivar was developed in a planned breeding program to produce unique container plants with showy flowers. The new cultivar originated from cross between Begonia taliensis, an unpatented plant, as the seed parent, and Begonia taliensis 12-0121, a proprietary, unreleased seedling, as the pollen parent.
Compared to the seed parent, Begonia taliensis, the new cultivar has smaller, more silver leaves on shorter petioles and has an upright branching habit rather than a rosette habit.
Compared to the pollen parent, Begonia taliensis 12-0121, the new cultivar has a larger habit with more palmate leaves that are more heavily silvered.
Compared to Begonia HOLIDAY™ ‘Snowflake’ (unpatented),the new cultivar is more spreading, better branched, and has larger female flowers that are retained for a longer period of time.
This selection is uniquely characterized by:                1. broad, maple-shaped leaves of glowing silver-white with mint green in a starry pattern along the veins,        2. bright red-pink sterile flowers,        3. an upright, bushy habit, perfect as a container plant,        4. a vigorous and well-branched bushy habit, and        5. excellent vigor.        
The new variety has been reproduced only by asexual propagation (leaf cuttings and tissue culture using apical tips). Each of the progeny exhibits identical characteristics to the original plant. Asexual propagation by micropropagation as done in Canby, Oreg., shows that the foregoing characteristics and distinctions come true to form and are established and transmitted through succeeding propagations. The present invention has not been evaluated under all possible environmental conditions. The phenotype may vary with variations in environment without a change in the genotype of the plant.